From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 33762381038 for ; Thu, 21 Aug 2025 20:08:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755806933; cv=none; b=bfiHBlYuNyi/3njoW0tqLnYPZhhtPF6pXa6cf/Qgh8kBXj2Li4Gy3buvw/5z/aAR9lB5KBys4K81AiFRe2mLbQiUE70G8LZhxGDtQurP5V363z8bLTNnXvrxfSZkQtdpqQo50VrZDXPrFAF4QfWjs2HcHDdx7hhHK70nvYw8hcA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755806933; c=relaxed/simple; bh=ncGz2ZUizfxPtBenqYCMYHXawyPm3K75je3+1YWzFIk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RreSzuUcwwodBN1I9LFGZnOg4uC7P3M5jUzbcHo6g7qek18zv2co7uSeMngWWzsDfxaN805swuyOdBJdrI9LZQp9qyysBqOO4UMIRDQJTfcPxAyLcE1fliLz6udFEnYHQqEMqKS+rp9OnxN6w91GuaKTBz8WKTYFQS3skZmzbvA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=T8Ob/AIN; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="T8Ob/AIN" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1755806929; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=G9hzYOZv6YXUN4v1wicJ53nqMhopJDezqYU76J2buLg=; b=T8Ob/AINvKh2RMkvW8+Zscd2y/k2+hoddH/iyMn3TQiRpL98bEcpfvhxmPvye/lXnlf08k xjeLp9SQAhX/gr2cW3znJB36481icKrm95jcpJB1M8rzERwo2uJz9HZjhGCbGgJo1MU0s4 EwSLWJmkkmVqW3radK9d79DA1dzcAMg= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-32-N1aY94Z2N0-oakDEg0z4lg-1; Thu, 21 Aug 2025 16:07:31 -0400 X-MC-Unique: N1aY94Z2N0-oakDEg0z4lg-1 X-Mimecast-MFC-AGG-ID: N1aY94Z2N0-oakDEg0z4lg_1755806850 Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-45a1b0045a0so8434395e9.0 for ; Thu, 21 Aug 2025 13:07:31 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1755806850; x=1756411650; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=G9hzYOZv6YXUN4v1wicJ53nqMhopJDezqYU76J2buLg=; b=n1sytrWn2EDKvHfflbAVi9pTM53KOTuQbzd38+7hU40flD/ULFp2vZnXQs+9IGAL/D /fBVg/JrcEUBubzmwJCPxklo9KGWwzub8u/t5kTl9m2OvSkVuUKwlvfzeu6q9fP+opog I9x7+oQiWu3s1O+2bRxxpxjpDnHerRldhmjEbMyKaLBT0odVq4E3P6YCEsipKlR/TIcj 0c+hbVxqIPoJdV6yB3NTnVgcPH3z7wVkg0FAZd+sodEoCDPyfrDqJDLUbKUjjuDeMqqb RleHqr6PKS40Y7qEPPI0MkXPnjxWyvpZOqF+y/1haHXscuwJATTZEbAIekhgSlVcG3cA R5MQ== X-Forwarded-Encrypted: i=1; AJvYcCUyHbfus5oSGPAcCcc4VCz702bZVX0CX7MVOPHiqb1kS3F6zHLPG/B3pf7JQbpHlSbt3ChGFFbEsSw=@vger.kernel.org X-Gm-Message-State: AOJu0Yxfa+YHsXs2wpQtUBVu4jwu5IpGqQ9KmRy4xdCi2NGLbGfGehZo 1dCOpxs0lMFd/fywNYJbHi7yXhfRgizssZdXID5EuZV7vfCJJ/3uKNpO+jBdnBBPx1OQA/xhkt3 G/BcRLwZNZ2YuKcU7TtBHa9bMRAwTJOjeMM0Rb2cXv1zG4C4a55y+7SRZSlxcqg== X-Gm-Gg: ASbGncsKiP/C34SdoCHUzw6X7ndTfPP0AKe4q7y0D7itAcD/v3TMWEuHRaowZvdSLC5 yND7uPCVrHeoRI/CVjdlryc7wpSM/2qil7zulDk1HHEJ57zm4s9qqQ/3erA8CDbQ3CcexJz/FHq xTsOwfgko808nbXDZdT9HJmHgnJpVjaE0sKUrq5EN5lemJorPGZbcyiOhsW+bYuUIjmBHVl2v2o CDYS63xVmbmNEaHpn7ylDZmw9SNzojrhZncconlb473jPcazY2xFMQP4XEUAzlFf0qGxQho+Pd2 wu9k9mMDbTTvp1bFgw1sTDXAulIZyb0iZAK3mERccttWdKCASx2TwkcGa5vnIJEyGnJnPlKPnqQ a23/5jyHBHzxE1zzFQv/5Dw== X-Received: by 2002:a05:600c:1548:b0:459:dfde:3329 with SMTP id 5b1f17b1804b1-45b517ddbe2mr2956165e9.31.1755806850064; Thu, 21 Aug 2025 13:07:30 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHPNoTdvVqQJqQwQf/z0aFpcDb/7HunF1Y6KwbAqmFFF4D3cnAaKEmAnoGbjwE6N5eIepmoyw== X-Received: by 2002:a05:600c:1548:b0:459:dfde:3329 with SMTP id 5b1f17b1804b1-45b517ddbe2mr2955545e9.31.1755806849496; Thu, 21 Aug 2025 13:07:29 -0700 (PDT) Received: from localhost (p200300d82f26ba0008036ec5991806fd.dip0.t-ipconnect.de. [2003:d8:2f26:ba00:803:6ec5:9918:6fd]) by smtp.gmail.com with UTF8SMTPSA id ffacd0b85a97d-3c3a8980ed5sm7242256f8f.16.2025.08.21.13.07.27 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 21 Aug 2025 13:07:29 -0700 (PDT) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: David Hildenbrand , Alexander Potapenko , Andrew Morton , Brendan Jackman , Christoph Lameter , Dennis Zhou , Dmitry Vyukov , dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, iommu@lists.linux.dev, io-uring@vger.kernel.org, Jason Gunthorpe , Jens Axboe , Johannes Weiner , John Hubbard , kasan-dev@googlegroups.com, kvm@vger.kernel.org, "Liam R. Howlett" , Linus Torvalds , linux-arm-kernel@axis.com, linux-arm-kernel@lists.infradead.org, linux-crypto@vger.kernel.org, linux-ide@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mips@vger.kernel.org, linux-mmc@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, Lorenzo Stoakes , Marco Elver , Marek Szyprowski , Michal Hocko , Mike Rapoport , Muchun Song , netdev@vger.kernel.org, Oscar Salvador , Peter Xu , Robin Murphy , Suren Baghdasaryan , Tejun Heo , virtualization@lists.linux.dev, Vlastimil Babka , wireguard@lists.zx2c4.com, x86@kernel.org, Zi Yan Subject: [PATCH RFC 08/35] mm/hugetlb: check for unreasonable folio sizes when registering hstate Date: Thu, 21 Aug 2025 22:06:34 +0200 Message-ID: <20250821200701.1329277-9-david@redhat.com> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250821200701.1329277-1-david@redhat.com> References: <20250821200701.1329277-1-david@redhat.com> Precedence: bulk X-Mailing-List: linux-ide@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Let's check that no hstate that corresponds to an unreasonable folio size is registered by an architecture. If we were to succeed registering, we could later try allocating an unsupported gigantic folio size. Further, let's add a BUILD_BUG_ON() for checking that HUGETLB_PAGE_ORDER is sane at build time. As HUGETLB_PAGE_ORDER is dynamic on powerpc, we have to use a BUILD_BUG_ON_INVALID() to make it compile. No existing kernel configuration should be able to trigger this check: either SPARSEMEM without SPARSEMEM_VMEMMAP cannot be configured or gigantic folios will not exceed a memory section (the case on sparse). Signed-off-by: David Hildenbrand --- mm/hugetlb.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 514fab5a20ef8..d12a9d5146af4 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -4657,6 +4657,7 @@ static int __init hugetlb_init(void) BUILD_BUG_ON(sizeof_field(struct page, private) * BITS_PER_BYTE < __NR_HPAGEFLAGS); + BUILD_BUG_ON_INVALID(HUGETLB_PAGE_ORDER > MAX_FOLIO_ORDER); if (!hugepages_supported()) { if (hugetlb_max_hstate || default_hstate_max_huge_pages) @@ -4740,6 +4741,7 @@ void __init hugetlb_add_hstate(unsigned int order) } BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE); BUG_ON(order < order_base_2(__NR_USED_SUBPAGE)); + WARN_ON(order > MAX_FOLIO_ORDER); h = &hstates[hugetlb_max_hstate++]; __mutex_init(&h->resize_lock, "resize mutex", &h->resize_key); h->order = order; -- 2.50.1